Joan Didion's Reconciling Detachment and Emotion

Didion has a striking ability to convey the
seeming superficiality or detachment of California culture during an era,
that was paradoxically very emotional and filled with intense
turmoil. Her ability to reconcile these two polarizing characteristics of
detachment and emotion is fascinating. Her essay about the
freeway culture of Los Angeles best exemplifies what I mean:

To understand what was going on it is perhaps necessary to have
participated in the freeway experience, which is the only secular communion
Los Angeles has. Mere driving on the freeway is in now way the same as
participating in it. Anyone can "drive" on the freeway, and many people
with no vocation for it do, hesitating here and resisting there, losing the
rhythm of the lane change, thinking about where they came from and where
they are going. Actual participants think only about where they are.
Actual participation requires a total surrender, a concentration so intense
as to seem a kind of narcosis, a rapture-of-the-freeway. The mind goes
clean. The rhythm take over. [83]

How does Didion use the physical infrastructure of the city to convey or
textualize the emotions of that period of which she herself was an active
participant?